Aristocystitidae

Belongs within: Diploporita.

The Aristocystitidae are a group of Lower Ordovician to Middle Silurian cystoids characterised by having the brachioles arising from facets directly adjacent to the mouth, with ambulacra exceedingly short.

Characters (from Kesling 1967): Theca ovate to elongate, typically tapered or constricted at aboral end, containing numerous, irregularly arranged plates. Column small and degenerate where present, absent in most forms. Most pores confined to one plate, canals simple, irregularly branched, or regularly divided to form typical diplopores. Brachioles arising from facets adjacent to mouth; ambulacra very short and unbranched, scarcely developed in some.

<==Aristocystitidae [Aristocystiden, Aristocystitida]
    |  i. s.: ‘Holocystites’ gyrinusSG93
    |--Campylostoma Dreyfuss 1939K67
    |    `--*C. grandis Dreyfuss 1939K67
    |--Pseudaristocystis Sun 1936 [=Dagoncystis Chauvel 1941]K67
    |    `--*P. dagon (Bather 1906) [=Aristocystis dagon, *Dagoncystis dagon]K67
    |--Lepidocalix Termier & Termier 1950K67
    |    `--*L. pulchrus Termier & Termier 1950 [=L. pulchrum]K67
    |--Amphoracystis Haeckel 1896K67
    |     `--*A. irregularis (Barrande 1887) [=Deutocystites irregularis]K67
    |--Hippocystis Bather 1919K67
    |    `--*H. subcylindrica (Barrande 1887) [=Aristocystites bohemicus subcylindricus]K67
    |--Baculocystites Barrande 1887K67
    |    `--*B. simplex Barrande 1887K67
    |--Trematocystis Jaekel 1899K67
    |    |--*T. subglobosa (Miller 1889) [=Holocystites subglobosus]K67
    |    `--T. hammelliK67
    |--Pachycalix Chauvel 1936K67
    |    |--*P. halli (Rouault 1851) [=Calix halli]K67
    |    `--P. pachythecusK67
    |--Sinocystis Reed 1917 [incl. Ovocystis Reed 1917]K67
    |    |--*S. loczyi Reed 1917K67
    |    |--S. mansuyi (Reed 1917) [=*Ovocystis mansuyi]K67
    |    |--S. segaudiK67
    |    `--S. yunnanensisK67
    |--Calix Rouault 1851 [incl. Dorycystites Kloucek 1917]K67
    |    |--*C. sedgwicki Rouault 1851K67
    |    |--C. dorecki Sdzuy 1955SG93
    |    |--C. lebescontiK67
    |    |--‘*Dorycystites’ purkynei Kloucek 1917K67
    |    `--C. rouaultiK67
    `--Aristocystites Barrande 1887 [=Aristocystis Bather 1889]K67
         |--*A. bohemicus Barrande 1887 [=*Aristocystis bohemicus; incl. Aristocystites grandiscutum Barrande 1887]K67
         |--A. desideratusK67
         |--A. gigasK67
         |--A. regularisK67
         |--A. rudisK67
         `--A. sinicusK67

*Type species of generic name indicated

References

[K67] Kesling, R. V. 1967. Cystoids. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa—Crinozoa (except Crinoidea) vol. 1 pp. S85–S267. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).

[SG93] Simms, M. J., A. S. Gale, P. Gilliland, E. P. F. Rose & G. D. Sevastopulo. 1993. Echinodermata. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 491–528. Chapman & Hall: London.